There is a way to salvage those frames with 4 pixels chopped off. I have experienced this problem recently with my asi071 camera. I've found a simple work around to this is to crop all images to match the smaller image size using DynamicCrop and image containers in pixinsight. Its a quick way to batch crop all your images to the correct size so they will stack. You have to do your flats, bias, and darks also this way for it to work.